Observation of correlations from collisionsV. Koptev1, M. Nekipelov1, 2, M. Büscher2, S. Dymov2, 3, M. Hartmann2, V. Hejny2, H.R. Koch2, N. Lang4, S. Mikirtichyants1, H. Ohm2, A. Petrus3, Z. Rudy2, 5, R. Schleichert2, A. Sibirtsev2, K. Sistemich2, H. Ströher2 and K.-H. Watzlawik2
1 High Energy Physics Department, Petersburg Nuclear Physics Institute, 188350 Gatchina, Russia
2 Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany
3 Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia
4 Institut für Kernphysik, Universität Münster, W.-Klemm-Str. 9, D-48149 Münster, Germany
5 M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, PL-30059 Cracow, Poland
(Received: 26 November 2002 / Revised version: 24 March 2003 / Published online: 20 May 2003)
Results of a first experiment on ( K+p) and ( K+d) correlations from proton-carbon ( pC) and proton-deuteron ( pd) interactions at beam energies above and much below the threshold for elementary kaon production in nucleon-nucleon reactions ( TNN=1580 MeV) are discussed. These data, obtained with the ANKE spectrometer at COSY-Jülich, provide first direct evidence for K+ production via the two-step mechanism and an indication for a cluster mechanism. It is shown that both processes contribute significantly in pC collisions at 1200 MeV, while they are strongly suppressed at 2300 MeV and also in pd-interactions at 1344 MeV. It is emphasized that the underlying kinematics can be exploited to distinguish between these reaction mechanisms.
13.60.Le - Meson production.
13.75.Jz - Kaon-baryon interactions.
14.40.Aq - , K, and mesons.
25.10.+s - Nuclear reactions involving few-nucleon systems.
© Società Italiana di Fisica, Springer-Verlag 2003